Comparison of the potential elastic energy stored and used by two antagonistic muscular groups.

The potential elastic energy stored and used by the flexors is compared to that of the elbow extensors in man. This comparison is made during a series of isolated and to-and-fro movements. The integrated EMG-work relationships are established for the isolated movements of flexion and extension and for the to-and-fro movements. For a same integrated EMG value: 1. The work done by the flexors or the extensors during to-and-fro movements is superior to that done during isolated movements. 2. In comparison to isolated movements the energy saved in to-and-fro movements is greater in the case of the extensors than in the case of the flexors. It appears that: 1. The extra work supplied during to-and-fro movements comes only from the extra positive work done after stretching. 2. The best performance of the extensors can be explained by the comparative study on the one hand of the potential elastic energy-force relationships and on the other hand the lever arm-elbow angle relationships for the Equivalent Flexor Muscle and the Equivalent Extensor Muscle.